Pin setting device using electrically detonatable cartridges



Feb. 10, 1970 HANS-DIETER SEGHEZZI 3,494,531

PIN SETTING DEVICE USING ELECTRICALLY DETONATABLE CARTRIDGES 3Sheets-Sheet 1 Filed Feb. 28, 1967 Qm m 3% VM INVENTOR. HANS- 'IERSA'GHEZZ/ ATTORNEYS Feb. 10, 1970 HANS-DIETER SEGHEZZI 3,494,531

PIN SETTING DEVICE USING ELECTRICALLY DETONATABLE CARTRIDGES Filed Feb.28, 1967 3 Sheets-Sheet 2 CURRENT SOURCE FIG. 5 BY Feb. 10, 1970HANS-DIETER SEGHEZZI 3,494,531

PIN SETTING DEVICE USIIiG ELECTRICALLY DETONATABLE CARTRIDGES Filed Feb.38, 1967 (5 Sheets-Sheet 3 A Tron/vars 3,494,531 PIN SETTING DEVICEUSING ELECTRICALLY DETONATABLE CARTRIDGES Hans-Dieter Seghezzi, Vaduz,Liechtenstein, assignor to Hilti Aktiengesellschaft, Schaan,Liechtenstein Filed Feb. 28, 1967, Ser. No. 619,241 Claims priority,application Great Britain, Mar. 5, 1966, 9,729/ 66 Int. Cl. B25c 1/08U.S. Cl. 2279 8 Claims ABSTRACT OF THE DISCLOSURE A cartridge-operatedsetting device for driving fastening means, such as nails, pins and thelike, into hard receiving materials, such as concrete and steel, by thedetonation of an electrically detonated cartridge is formed with a guideportion, for the fastening means, a handle portion, and a cartridgechamber, and the detonation of an electrically detonatable cartridge inthe cartridge chamber projects a piston or the like to drive thefastening means into the receiving material.

A pair of electric terminals is provided at the cartridge chamber ininsulated relation to each other, and an electric detonating circuit isprovided for connection to a source of electric potential, thisdetonating circuit includ ing respective conductors connected to theterminals. At least one safety switch means is connected in thedetonating circuit and is closed only when the parts of the device arein position to drive a fastening means. Furthermore, at least one deviceactuating switch is connected in the circuit and to the safety switchmeans in such a manner that both the safety switch means and theactuating switch must be closed for the device to be actuated.

In one embodiment of the invention, the device is arranged to beconnected to an external source of electric potential and, in anotherembodiment of the invention, a source of electric potential is mountedor enclosed in the device. In this latter embodiment, a chargingcondenser is included in the detonating circuit and is charged to arelatively high voltage when the actuating switch has one of twopositions, this condenser discharging through the detonating circuit andthrough the electrical terminals when the actuating switch has its otherposition and the safey switch means is closed.

BACKGROUND OF THE INVENTION Known cartridge-operated setting devices fordriving fastening means into hard receiving materials use cartridgeswhich are detonated by percussion impact. In order to prevent undesireddetonation, such a device must comprise a relatively expensivedetonating mechanism and associated safety devices. There is a distinctdisadvantage, both from the standpoint of economics and from thestandpoint of safety, with respect to setting devices usingimpact-detonated cartridges.

SUMMARY OF THE INVENTION The invention relates to cartridge-operated pinsetting devices for the driving of fastening means, such as nails, pinsand the like, into hard receiving materials such as concrete and steel,and, more particularly, to an improved cartridge-operated pin settingdeviceutilizing electrically detonated cartridges.

The cartridge-operated setting device of the invention is intended as asimple and safe setting device for these fastening means, and the safetyis enhanced by the use of electrically detonated cartridges. The use ofelectrically detonated cartridges, as compared to the percussion- StatesPatent detonated cartridges, has certain advantages with respect to boththe cartridge and the setting device proper.

In accordance with the invention, a cartridge-operated pin settingdevice comprises housing means including a guide portion, a handleportion and a cartridge chamber. Two electrical terminals are providedat the cartridge chamber and are insulated from each other, and adetonating circuit is provided for connecting the terminals to a sourceof electric potential, this detonating circuit including respectiveconductors connected to the terminals. The detonating circuit furtherincludes at least one safety switch means which is closed only when theparts of the device are in position to drive a fastening means, and alsoincludes at least one device actuating switch connected to the safetyswitch means in such a manner that both the safety switch means and theactuating switch must be closed in order for the device to be actuatedto drive a fastening means.

The two terminals arranged at the cartridge chamber are so positionedthat they are cngageable with the terminals of an eletcrically detonatedcartridge positioned in the cartridge chamber. The safety switch meansassures that detonation of the cartridge is possible only if the deviceis pressed against a receiving material with a certain minimum pressure.The electrically detonatable cartridge is so designed that it can bedetonated only at a preset minimum voltage or amount of ignition energy,but cannot be detonated by a percussion impact. Thus, the pin settingdevice of the invention does not require the ignition pin required inknown devices, nor does it require the moving parts associated with theignition pin.

The pin setting device of the invention may be connected to any currentsource which, either directly or through a transformer, will supply therequired ignition potential or energy. For certain kinds of use, whereinconnection of a commercial supply circuit is not possible, it isadvantageous, according to one embodiment of the invention, to installthe current source either in or immediately adjacent the setting device.In this case, a particularly suitable current source is a rechargeablebattery having a capacity advantageously selected so as to permit thedriving of at least 1000 fastening means before recharging of thebattery becomes necessary. In such event, recharging may be effectedovernight. When utilizing such a battery, known means for transformingthe potential are used.

In accordance with a further feature of the invention, it isadvantageous to use a condenser and to construct the device actuatingswitch so as to have two switching positions. In one position, thedevice actuating switch closes a circuit including the current sourceand the condenser, for charging of the condenser. In its other position,the device actuating switch electrically connects the condenser to thecartridge chamber terminals. In the latter position, if the safetyswitch means is closed simultaneously with the actuating device closedto the firing position, the condenser discharges through theelectrically detonated cartridge in the cartridge chamber, thusdetonating the cartridge.

An object of the invention is to provide a simple and safe pin settingdevice.

Another object of the invention is to provide a simple and safe pinsetting device designed to use with electrically detonated cartridges.

A further object of the invention is to provide a cartridge-operatedsetting device, for use with electrically detonated cartridges, andhaving advantages with respect to both the cartridge and the deviceproper.

Yet another object of the invention is to provide a cartridge-operatedpin setting device including housing means having a guide portion, ahandle portion and a cartridge chamber, and further including electricalterminals at the cartridge chamber and insulated from each other.

A further object of the invention is to provide such a pin settingdevice including a detonating circuit for connecting the terminals to asource of electric potential, with the detonating circuit including atleast one safety switch means and at least one device-actuating switch.

Still another object of the invention is to provide such acartridge-operated setting device utilizing electrically detonatedcartridges which can be detonated only upon the application thereto ofat least a minimum preset potential.

A further object of the invention is to provide a cartridge-operatedsetting device using electrically detonated cartridges and arranged forconnection to an outside source of potential.

Still another object of the invention is to provide a cartridge-operatedsetting device utilizing electrically detonated cartridges and having aself-contained source of electric potential.

An ancillary object of the invention is to provide a cartridge-operatedsetting device utilizing electrically detonated cartridges and whichdoes not require the moving parts necessary with setting devicesutilizing percussion impact detonated cartridges.

BRIEF DESCRIPTION OF THE DRAWINGS For an understanding of the principlesof the invention, reference is made to the following description oftypical embodiments thereof as illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a longitudinal sectional view through one form of acartridge-operated setting device embodying the invention, and showing.a source of electric potential connected thereto;

FIG. 2 is a schematic wiring diagram related to the device shown in FIG.1;

FIG. 3 is a partial longitudinal sectional view through another form ofcartridge-operated setting device embodying the invention;

FIG. 4 is a schematic wiring diagram related to the setting device shownin FIG. 3; and

FIG. 5 is a complete wiring diagram related to the setting device shownin FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, thepin setting device 1 shown therein comprises a hollow body 2 which isclosed at one end. A handle 3 projects laterally from body 1 close tothe closed end of the latter. At its closed end, body 2 is formed, inits interior, with an annular groove 4 defining a projection 5 havingtwo parallel bores 6 and 7 therethrough to receive current conductors.The forward ends of bores 6 and 7 are formed with large recesses toreceive dielectric material 8 for the cartridge chamber terminals. In ahollow space adjacent the closed end of body 2 and handle 3, there is asafety switch 16 Whose actuating button 16:: faces away from handle 3.

A trigger lever 21 is arranged in a forwardly opening recess 22 inhandle 3, and a spring 23 biases trigger 21 outwardly of recess 22. Theinner edge of trigger 21 is in contact with the actuating button 17a ofan actuating switch 17. In order to close switch 17, trigger 21 must bepushed, against the force of spring 23, and opposite to the drivingdirection of the device.

Two insulated recesses 25 and 26, for accommodation of the terminals ofpotential or current source 15, are located in the outer end portion ofhandle 3, and receive respective electric contacts 13a and 14a forconductors 13 and 14. Conductor 14 extends from contact 14a to aterminal 12 at cartridge chamber 10, while the other conductor 13extends from terminal 13a, through actuating switch 17 and safety switchmeans 16, to terminal 4 11 at cartridge chamber 10. A detachable closingplate 27, located at the rear ends of body 2 and handle 3, enablesinstallation and exchange of the conductors.

Within the housing formed by hollow body 2, there is located a guideportion whose outer portion 28 is formed with an annular recess 29facing rearwardly. A spring 30 has one end engaged in recess 29 and itsother end engaged in recess 4 of body 2. A pin guide 31 is engaged inportion 28, and has a flange 31a engaging the forward end of portion 28.Pin guide 31 extends axially only over about half the length of portion28. Its forward end has a recessed bore 32 for accommodating a fasteningmeans, and a recess bore 33 at the rear end of element 31 receives oneend of a spring 35 whose other end is engaged with stroke piston 34 andbiases the stroke piston back .to the starting position.

Stroke piston 34 comprises two portions, a smaller diameter shaft 34awhich is slidably engaged in guide 31 and a larger diameter shaft 34bwhich is slidably engaged in the outer portion 28 of the guide portion.The forward end of shaft 34a of piston 34 is formed with a bore 36serving as a guide for the head portion of the fastening means.Cartridge chamber 10 is located in portion 34b of piston 34, at the rearend of the piston. Electrical connection of the terminals or contacts ofan electrically detonatable cartridge, placed in cartridge chamber 10,with the terminals 11 and 12 at the cartridge chamber is possible onlyby pressing the guide portion rearwardly against the bias of spring 30.

During such rearward pressure, actuating button of safety switch means16 is depressed. By then pressing trigger 21, the detonating circuit isclosed by actuating switch 17. Exchanging of cartridges can be effectedby opening of a known bayonet lock (not shown) whereupon the guideportion may be removed from housing 2.

Referring to the schematic wiring diagram shown in FIG. 2, cartridge 37is connected to potential source 15 through terminal 12 and conductor14, as well as through terminal 11, safety switch means 16, actuatingswitch 17, and conductor 13.

FIG. 3 is a partial longitudinal sectional view, illustrating the rearportion of a preferred embodiment of the invention device in a positionin which it is pressed against the receiving material. This portioncontains the parts essential to the invention. The front portion, whichis not illustrated, is constructed in a known manner and preferably sothat'the device may be opened by turning and raising the front portion.

The device shown in FIG. 3 comprises a metallic housing 40 includingportions 40a, 40b and 40c. A metal handle portion 60 is located at therear end portion of housing 40, and a metal guide portion 41 is arrangedaxially displaceably within portion 40a of the housing. Guide portion 41is preferably constructed in a known manner to accommodate a piston,which has not been shown. The rear or inner end portion of guide portion41 is formed with a conical cartridge chamber 10, accommodating anelectrically detonatable cartridge 37, preferably having a plastic caseand including electric contacts 38 and 39. The area of housing portion40c adjacent terminal 39 constitutes the terminal 12 located at thecartridge chamber, and the other terminal 11, cooperating with terminal38 of the cartridge, is formed by a contact pin 13 which is embedded ininsulating material 42 and thus insulated from housing 40.

The rearward part of portion 400 of housing 40 is reduced in diameter todefine a recess 44a seating a spring 44 whose rearward end is engagedwith a ring 43 projecting inwardly from housing portion 4017, theportion 400 further having a pin 70 projecting rearwardly therefrom andformed with a notch 71. The setting device has to be pressed against thereceiving material sufficiently to overcome the bias of spring 44 inorder to bring contact pin 13 into electrical contact with a terminal45, thus closing safety switch means 16. Contact 45 is connected to oneterminal of a battery 18 located directly at bracket 60a of the handleportion. The other terminal 46 of battery 18 is in contact with bracket60a of the handle portion and thus metallically connected electricallyto terminal 39 of portion 400 adjacent the cartridge.

Safety switch means 16 is complemented by a pivot lever 49 which ispivoted on a pin 50 and serves as an additional safety element. Pivotlever 49 comprises two arms, arm 49a and arm 49b. Arm 49a extendsforwardly and comprises, at its outer end portion, a projection 72 forengagement in recess 71 of projection 70 of portion 400, recess 71 beingarranged immediately inwardly of projection 72. Arm 49b extendsrearwardly and rests against a trigger 47 which is pivotal about pin 48.

If, as shown in FIG. 3, the setting device is pressed against areceiving material, actuating trigger 47 will press arm 49b of pivotlever 49 upwardly, and arm 49a will thus be pressed downwardly orinwardly. Since the projection 72 of arm 49a then engages into recess71, actuating button 17a of actuating switch 17 is depressed to anextent such that switch 17, and thus the detonating circuit, are closedand cartridge 37 is detonated. If the setting device is not pressedfirmly against the receiving material, projection 72 will not be alignedwith recess 71, but will be opposite the portion of the pin 70 which isrearwardly beyond recess 71. Thus, arm 49a will be prevented from beingpressed downwardly sufiiciently to close the circuit by actuating switch17. The actuation of pivot lever 49 requires that the force of a spring51 be overcome. The portion 49, including the terminals 45 and 46 aswell as actuating switch 17, further comprises means for transformingthe voltage, such as shown in FIG. 5. Battery 18 is exchangeablyconnected, by means of plugs 52, to portion 19. The handle portion isdefined by a handle 60b which is secured in place by screws 61 and 62.

Referring to FIG. 4, which is a schematic diagram of the electricalcircuitry of the device shown in FIG. 3, battery 18 which, for example,may be a 12 volt battery, is electrically connected to box 19 containingthe components required for transforming the voltage. A condenser 20,through conductors 13 and 14 and actuating switch 17, is connected tothe box 19. The cartridge chamber terminals 11 and 12, together withcartridge 37 and safety switch means 16, is arranged in parallel withcondenser 20. Wit-h the position of actuating switch 17 shown in FIG. 4,condenser 20 is, for example, at a voltage of 120 volts as provided froma transformer. After closure of safety switch 16 and operation ofactuating switch 17 into its other position, the thus charged condenseris discharged across cartridge 37 and thus detonates the cartridge. Inthe particular example illustrated, the recharging time for condenser 20is 8 seconds, which is sufiiciently fast, since the time required forinserting a new cartridge and a new pin is at least this long.

FIG. illustrates the detailed wiring diagram of the device according toFIG. 3, and includes a transformer 53, switches 54, 55 and 56, andvarious other components such as a transistor and a diode. Switch 55 isin the battery charging line and is normally open, thus preventing shortcircuiting of battery 18 due to dirt, water and the like.

Switch is closed when the battery Charging plug is inserted. Switch 56is connected in parallel with condenser 20 and enables the discharge ofcondenser 20. By actuating switch 54, condenser 20 is charged whenactuating switch 15 is in the illustrated position and discharged whenactuating switch '17 is moved to its other position.

What is claimed is:

1. A cartridge-operated setting device for driving fastening means, suchas nails, pins nd the like, into hard receiving materials, such asconcrete and steel, comprising, in combination, housing means forming aguide portion for the fastening means, a handle portion and a cartridgechamber for electrically detonated cartridges; 3. pair of electricalterminals within said cartridge chamber in insulated relation to eachother, for connection to the terminals of an electrically detonatedcartridge inserted into said chamber; and electric potential applyingcircuit connectable to a source of electric potential and includingrespective conductors connected to said terminals; at least one safetyswitch means connected in said circuit and closed only when the parts ofsaid device are in position to drive a fastening means; and at least onedevice actuating switch in said circuit and connected to said safetyswitch means in a manner such that both said safety switch means andsaid actuating switch must be closed to actuate said device.

2. A device, as claimed in claim 1, including a detonating potentialsource physically associated with said device.

3. A device, as claimed in claim 2, in which said detonating potentialsource includes a battery and means operatively connected to saidbattery and operable to develop at least a preset detonating potential.

4. A device, as claimed in claim 3, in which said battery isrechargeable.

5. A device, as claimed in claim 3, in which said detonating potentialsource includes a condenser; said actuating switch having a pair ofpositions in one of which it closes a condenser charging circuitincluding said potential source and said condenser and in the other ofwhich it completes an electric circuit including said condenser and saidelectrical terminals.

6. A device, as claimed in claim 3, in which said housing means is metaland constitutes one of said conductors.

7. A device, as claimed in claim 5, in which said housing means is metaland constitutes one of said conductors.

8. A device, as claimed in claim 1, including interlocking safety meanspreventing closure of said actuating switch except when the parts ofsaid device are in position to drive a fastening means.

References Cited UNITED STATES PATENTS 2,780,810 2/1957 Catlin et a12279 2,931,039 4/1960 Henning et al 227--11 3,150,488 9/1964 Haley 22793,361,064 1/1968 Johnston et a1. 1028 BERNARD STICKNEY, Primary ExaminerUS. Cl. X.R.

